MitropolskyY. A. and FоdchukV. I. (1966) “Asymptotic methods of nonlinear mechanics as applied to nonlinear differential equations with delayed argument”, Ukrains’kyi Matematychnyi Zhurnal, 18(3), pp. 65-84. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8738 (Accessed: 24November2024).